This invention pertains to a method and means for bolting together elements having holes which are so large or irregularly shaped that they fit loosely around the bolt. Apart from lacking in strength, such elements are sometimes even difficult to bolt together. The method of this invention is particularly important wherein end uses demand that the elements fit tightly around the bolt. In one of its aspects the invention compensates for bolt holes of different sizes when multiple elements are being bolted together. In another of its aspects the invention applies to elements, and especially to composites, whose bolt holes were not formed at close tolerances, but whose end use demands a close tolerance fit.
In the space shuttle, a cargo bay storage rack was required which was to be manufactured from a metal-plastic composite and bolted to a cargo bay structure. Following completion, utilization of the rack was disallowed due to tolerances, that is, the size differences between the outside bolt diameter and the inside hole diameter. For acceptance the hole had to have a close tolerance fit with the bolt. Close tolerance means no more than 0.002 inch clearance between the bolt and the edge of the bolt hole. Upon investigation it was found that the required bolt-bolt hole tolerances were painstakingly, if not prohibitively, exacting to achieve.
In addition to the space shuttle problem there are other close tolerance requirements for bolts, for instance, plates or flanges on instruments, machines and pipes which are subjected to vibrations and shock. Large instruments, pipelines and other apparatus in rooms housing generators and the like often benefit from close tolerance bolting. However frequently such fabrication is not cost effective. There is a need, then, for means of achieving close tolerances between bolts and bolt holes without machine tooling. Such means are provided herein, along with a method for accomplishing the end result.